Preheat the oven to 350 degrees F. Generously grease a 10- or 12-inch bundt cake pan with butter - making sure to grease all the nooks and crannies really well.
Sprinkle the brown sugar over the bottom of the pan, then layer the cranberries evenly over the sugar.
In a medium bowl, whisk together the flour, baking powder, baking soda and salt.
In a large bowl (or in the bowl of a stand mixer), combine the granulated sugar together with the zest from the lemons. Rub the zest into the sugar with your fingers until the sugar is infused with the lemon fragrance.
Add the butter to the bowl with the lemon sugar and, using the paddle or whisk attachment on the stand mixer or a handheld electric mixer, beat on medium-high speed until light and fluffy, about 2-3 minutes. Add the vanilla and the eggs, one at a time, mixing and scraping down the sides of the bowl as needed.
In a liquid measuring cup, combine the buttermilk with the 2 tablespoons lemon juice.
Add 1/3 of the dry ingredients. Mix until just combined and a few dry streaks remain. Add 1/2 of the buttermilk/lemon mixture. Mix again until just combined.
Add another 1/3 of the dry ingredients and mix until just combined, followed by the remaining 1/2 buttermilk/lemon juice mixture. Mix. Add the final 1/3 of the dry ingredients and mix until just incorporated.
Spread the batter carefully into the prepared pan over the cranberries.
Bake for 45-55 minutes or until lightly golden on top and just set.
Transfer the bundt pan to a wire rack and let cool about 10 minutes. Invert the cake onto a serving platter, tapping lightly so the cake falls out. Let the cake cool completely.
For the glaze, combine the powdered sugar with the 1 1/2 tablespoons lemon juice and whisk until smooth. Add additional lemon juice or milk for a thinner consistency, if needed.
Drizzle the glaze over the cooled cake and let set, 5-10 minutes, before slicing and serving.
Notes
Cranberries: I've only ever made this cake using fresh cranberries but I suspect frozen would work well, too.Lemons: you'll need 2-3 lemons for this recipe - make sure to zest the lemons before juicing them! Don't Overmix: as always, don't overmix that batter! Follow the instructions and mix each addition of liquid/dry ingredients until just incorporated.